This invention relates in general to fastening devices and, more particularly, to fastening devices for attaching liner segments to a backing.
Chutes and other conduits through which abrasive materials are conveyed wear out quite rapidly unless protected against the abrasive action of the materials. For this reason such conduits are often comprise a metal shell lined with hard refractory materials such as aluminum oxide.
One procedure for achieving this end is to install the refractory tiles against the shell of the conduit by means of tapered plugs. Each tile has at least one tapered hole into which a tapered plug fits. When the plug is fully inserted, it is completely recessed within the tile and has its inner end located near the metal shell. The inner end furthermore has an aperture through which the metal shell is exposed. The plug is secured to the shell merely by inserting a welding rod through the aperture and striking an arc with the metal shell so as to produce a bead between the inner end of the plug and the shell. This procedure is disclosed in U.S. Pat. Nos. 3,624,344 and 3,747,291.
While the tiles may be flat, the conduit shells against which they are installed often are not, and as a consequence the individual tiles must often be set into a grout bed to level them. This displaces the plugs from the shell, making it difficult to build a bead between the two. Also, most plugs merely fit loosely into their tapered holes, so it is difficult to maintain them tightly seated as they are welded to the shell. Furthermore, replacement of the tiles on an individual basis is not an easy undertaking, for it requires cumbersome arc welding equipment.